NAME

SYNOPSIS

DESCRIPTION

The
umask()
function sets the process' file mode creation mask to
cmask
and returns the previous value of the mask.
Only the file permission bits of
cmask
(see
<sys/stat.h>)
are used; the meaning of the other bits is implementation-dependent.

The process' file mode creation mask is used during
open(),
creat(),
mkdir()
and
mkfifo()
to turn off permission bits in the
mode
argument supplied.
Bit positions that are set in
cmask
are cleared in the mode of the created file.

RETURN VALUE

The file permission bits in the value returned by
umask()
will be the previous value of the file mode creation mask. The state
of any other bits in that value is unspecified, except that a
subsequent call to
umask()
with the returned value as
cmask
will leave the state of the mask the same as its state before
the first call, including any unspecified use of those bits.